Friday, February 8, 2008

Lessons in Birdsong

Despite the chattering that marks this and every political season, it turns out that learned vocalization is pretty rare in nature.

Aside from humans, only whales, dolphins, bats and several species of songbirds (and perhaps elephants and sea lions) exhibit learned vocalization, which basically means the inborn ability to hear, imitate and repeat sounds. This ability differs from, say, a dog’s bark, which may communicate to its owner that it’s chow time, but the actual sound is an inborn and not a learned vocal trait.

For the past decade, neurobiologist Erich Jarvis (photo) of Duke Medical Center has used songbirds as models to probe the genetics and molecular biology of vocal communication. In a recent lecture in the Genomes@4 series sponsored by the Duke Institute for Genome Sciences & Policy, Jarvis recounted -- complete with whistling and other sound effects -- some highlights of his laboratory’s research. The findings have gained widespread scientific and popular attention, as reported here, here and in a video here.

Among recent efforts, Jarvis and his colleagues have found that the more birds sing, the more genes become active, with increased numbers of genes in their brain cells exhibiting heightened activity. Another case of use it or lose it -- or never get it.

And not to give away secrets, his group has just made some intriguing observations by analyzing birds as they hop and sing at the same time -- that is, while several types of brain and neuromuscular activities are under way. As the group will report in an upcoming issue of the online, open-access journal PLoS, these observations suggest that production of learned vocalizations ignites a number of specific genes that have been carried over from an ancient regulatory system.

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